ISSN:
0025-116X
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Linear polybiurets can be synthesized by polycondensation of chloroformyl isocyanate and N,N′-bis(trimethylsilyl)-α,ω-diaminoalkanes or silylated aromatic diamines. The polybiurets were characterized by elemental analyses, inherent viscosity measurements, IR spectroscopy, 1H, 13C, 15N NMR spectroscopy in solution, differential scanning calorimetry (DSC) measurements, wide-angle X-ray scattering (WAXS) and thermogravimetric analyses. All polybiurets are semicrystalline materials with a low rate of crystallization and unexpectedly low melting points. 13C and 15N NMR cross-polarization/magic angle spinning (CP/MAS) spectra of the solid polybiurets indicate different conformations for the amorphous and crystalline phase. All polybiurets gradually decompose upon heating above 200°C. Synthetic methods and properties of linear biurets were also checked by synthesis and characterization of N,N′-dioctylbiuret.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1992.021931012
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